Five years ago, Koki Kimura pulled off an unthinkable turnaround to save his company. Now, he's trying to do it again.

The 42-year-old runs a tech company called Mixi Inc., a firm with one of the most tumultuous corporate histories in Japan. It operated the country's most popular social network for years — until Facebook showed up. Then Kimura led the games business to develop "Monster Strike," which became the most lucrative mobile game in history. Now, with profits slowing and a scandal over concert tickets claiming the job of his predecessor as president, Mixi needs another reinvention.

Four months into his new role, Kimura thinks he has the answer: a new digital product that combines the entertainment of watching traditional sports with the interactivity of video games. The unveiling is months away, but Kimura suggests it could be like watching LeBron James' Lakers with friends while competing to predict specific outcomes — such as how many points a player will get or how many fouls.